Vol no. 6: Clays in several parts of Kentucky, with some account of sands, marls and limestones. I. Kaolins and plastic clays on the eastern rim of the western coalfield; Notes on clays in the western lead, zinc and spardisteict (F. J. Fohs);Clays and sands of Jackson's purchase; Clays in the Red River Valley; by James H.Gardner. II. Clays of Silurian, Devonian, Waverly and Irvine formations. By Aug. F. Foerste. III. Analyses of Miscellaneous Kentucky clays.